Alan Bell, executive vice president of advanced technology explained to NewScientist.com how the scheme works; basically it alters the audio of a movie in way inaudible to listeners, but that creates a specific digital pattern HD-DVD players pick up on. If it detects the signal, it will refuse to play the disc. One form of the technology will be included in every movie played in cinemas to prevent people aiming camcorders at the screen and recording the movie, and another for home movies to detect if it is an authentic factory-pressed version.
Check the article for more details and another researchers opinion on possible issues. Do you think this is an effective/necessary form of DRM and does it make you more or less likely to select an HD-DVD player?